CHRISTINA AGUILERA‘s soon-to-be-ex-husband fears their son could be in danger after the troubled pop star and her new boyfriend were busted on alcohol-related charges.

The 30-year-old "Dirrty" singer made headlines earlier this month when she was arrested in Los Angeles for public drunkenness. Christina was in the passenger seat when her new beau, 25-year-old Matt Rutler, was busted for DUI.

Now Christina’s worried ex, Jordan Bratman – father of her 3-year-old son Max – is hoping that she will keep their preschooler away from her alcohol-fueled relationship with Rutler.

"Jordan knows that Christina has been on a downward spiral since she began dating Matt, but he can’t believe that as a mother, she would risk her life by getting in a car with someone who was over-the-limit drunk," maintained a source close to 33-year-old music executive Jordan.

The former couple, who were married for five years, finalized their divorce settlement in February and currently share custody of Max.

"After the arrests, I think Jordan fears for Max’s safety when he’s with Christina and Matt," continued the source.

Since Christina’s marriage collapsed, the award-winning singer – who recently signed on as a singing coach on NBC’s new singing competition series "The Voice" – has been photographed partying with her young boyfriend on numerous occasions. The pair started dating after meeting on the set of her movie "Burlesque." He works as a set assistant and musician.

After mangling the words to the "National Anthem" at the Super Bowl on Feb. 6, Christina fell onstage after her performance at the Grammy Awards. A week later, the Internet was abuzz with speculation that she was drunk at the ceremony.

In early January, she reportedly drank so heavily that she passed out on a bed during a birthday party at "Hurt Locker" actor Jeremy Renner’s house.

"Jordan must feel like Matt has been a horrible influence on Christina. Idon’t think he has ever felt comfortable leaving Max in Christina’s care when Matt is there," added the source.

"He’s praying that Christina will seriously heed his warning, not only for the sake of their child, but of the stars involved!